1. Field of the Invention
The present invention relates to a method for manufacturing a microcrystalline semiconductor film and a method for manufacturing a semiconductor device which uses the microcrystalline semiconductor film.
In this specification, a semiconductor device means all types of devices which can function by utilizing semiconductor characteristics, and a display device, an electro-optical device, a photoelectric conversion device, a semiconductor circuit, and an electronic device are all semiconductor devices.
2. Description of the Related Art
As one type of field-effect transistor, a thin film transistor whose channel region is formed using a semiconductor film that is formed over a substrate having an insulating surface is known. Techniques in which amorphous silicon, microcrystalline silicon, or polycrystalline silicon is used for a semiconductor film used for a channel region of a thin film transistor have been disclosed (see Patent Documents 1 to 5). A typical application of thin film transistors is a liquid crystal television device, in which thin film transistors have been put to practical use as a switching transistor for each pixel that constitutes a display screen.
A photoelectric conversion device is being developed in which microcrystalline silicon, which is crystalline silicon capable of being manufactured by a plasma CVD method, is used in a semiconductor film having a function of photoelectric conversion (for example, see Patent Document 6).